Bohol can rely on up to 90 megawatts (MW) of power supply from Leyte through the Leyte-Bohol Interconnection Project (LBIP) via the Ormoc-Maasin-Pitogo-Ubay submarine cable.
The National Grid Corporation of the Philippines (NGCP) assured this, having maximum capacity supply of 90 megawatts that is way beyond Bohol’s actual daily power consumption that fluctuates from 55-56 MW.
For this range of consumption, NGCP caps the maximum supply to 60 MW.
Bohol’s maximum supply peaked to 76 MW on May 5, the highest so far in the early part of 2017.
Bohol relies on LBIP for 87 percent of its power consumption which is projected to rise to 75 megawatts by 2019 and up to 113 megawatts by 2043, considering economic growth in the province.
The National Grid Corporation of the Philippines runs with an efficient High Voltage Direct Current (HVDC) link on an area control (AC) network.
NGCP’s HVDC facility in Ormoc houses the P10-billion converter which is the most expensive and vital component of the national grid.
Sisinio Quindao, chief engineer of HVDC Ormoc Converter Station, explained said the Leyte-Luzon interconnection is a 440 MW, 350 kV monopolar HVDC link, and has a total transmission distance of 452 linear kilometers.
“It normally transfers power from the geothermal power plants in Leyte to the southern part of the main island of Luzon.However, this present time it takes power from Luzon Grid to cope up the power deficiency in the Visayas Grid,” according to Quindao.
Both Luzon and Visayas Grid benefited the inherent stabilizing effect of the HVDC link on an AC network.
Quindao further explained that the HVDC serves as the rectifier or converter of high voltage power coming from a supplier passing through a transmission line and going to the distribution system and then again converted to a lower voltage form before going to the individual household or power consumer.
It serves as the equalizer of the frequency or voltage energy that passes before going to the distribution system.
All supply going to Bohol pass through Leyte transmission line network.
Quindao, further explained that NGCP has a total of 1,589.31 linear kilometers or 2,101.88 CKM for Transmission Line Network.
This includes the Leyte-Samar Transmission Line Network spans 259 line kilometers of 350-kilovolt transmission line.
It spans from Ormoc to Cabacungan in Northern Leyte.
A 350-kV transmission line is the highest of all voltage capacity levels.
The Emergency Restoration System (ERS) is on standby in case transmission towers are toppled during typhoons.
In October 2014, NGCP completed the Bohol Backbone Transmission Project (BBTP).
BBTP now accommodates load growth and addresses low voltage limitations in the island.
Components of the project are the 92.27 circuit-kilometers of 138-kiloVolt (kV) overhead transmission lines from Ubay to Corella, and 9 circuit-kilometers of 69-kV transmission lines from Corella to Cortes, utilizing steel tower and steel pole structures, respectively”.
NGCP also expanded the Ubay Substation and constructed “a new 100-megavolt ampere (MVA) substation in Corella”.
In a press statement, NGCP also made it known that it “is poised to undertake several major facility improvement programs this year”.
“Among the projects NGCP is pursuing are the Luzon 500kV backbone to accommodate incoming generating plants, the Cebu-Negros-Panay backbone to improve power sharing between the major islands, and the Mindanao 230kV backbone to reinforce the Mindanao grid as new plants come online,” according to NGCP.
The Leyte-Luzon HVDC interconnection project was started on September 1, 1994 and it then had its commissioning on March 17, 1998. Its commercial operation started on August 6, 1998.
The project includes the Ormoc Converter Station and the Naga Converter Station.
The Ormoc Converter Station has rated capacity of 440,000 kilowatts, voltage rating of 350 kV direct current, rated current of 1,300 amperes.
The length of Over Head Transmission Lines (OHTL) to cable terminal station (CTS) spans 259 kilometers.
Its submarine cable has length of 2X21 kilometers, and its electrode line spans 23 kilometers.
The EDC Leyte Geothermal Business Unit (LGBU) is one of the World’s largest wet steamfield with over 700 MW of installed geothermal capacity with contract area of 115,552 hectares, total plant capacity of 701 MW, 87 production wells, 40 reinjection wells, and pipe network of 73.6 kilometers.
It consists of four geothermal power plants- -the Tongonan I, Upper Mahiao, Malitbog and Mahanagdong.
The Tongonan I steamfield project was commissioned in 1983 and was the first geothermal energy project developed by Energy Development Corporation.
EDC is the leading renewable energy company in the Philippines, generating 23 percent of the total installed renewable energy in the country
Today, EDC is a vertically integrated renewable energy company with operations located across the country.
The integrated steamfield and power plants produce 1,169 MW from geothermal power, 132 MW from hydro, 150 MW from wind, and 7 MW from solar.
The measured temperature profile beneath the Greater Tongonan Geothermal Field indicates two distinct heat sources.
The Greater Tongonan Geothermal Field in Leyte is a large liquid-dominated steamfield that is composed of two distinct reservoirs.
The Leyte Geothermal Production Field and Power Plants- -in Upper Mahiao with 131.86 MW capacity, Tongonon with 112.5 MW, South Sambaloran/Malitbog with 232.5MW, Mahanagdong-B with 60 MW, and Mahanagdong-A with 120MW capacity.
Mindanao station 1 produces 52MW while Mindanao II produces 54 MW.
The wind and solar power came from Ilocos Norte- -150 MW from Burgos Wind and 7 MW from Burgos Solar Plant I and II.
Hydro Power from Luzon came from Pantabangan Plant that produces 120 MW, and Masiway for 12.5 MW.
The EDC steamfields and its subsidiary power plants include Bacman I and II, Tongonan in Leyte and Palinpinon in Valencia, Negros Oriental.
EDC produces 120 MW from Bacman I, 20 MW from Bacman II, 112.5 MW from Tongonan I, and 112.5 MW from Palinpinon I and 80 MW from Palinpinon II.
Steam from W401 in Upper Mahiao led to commissioning of 3 MWe powerplant in 1977.
The 112.5MWe Tongonan Geothermal Power Plant (TGPP) was constructed in 1980-1983.
The expansion of Tongonon-1 (650MWe) followed in 1994-1997.
In 1973-1976, drilling of exploration wells was conducted with technical assistance by New Zealand scientists where the New Zealand government led the exploratory drilling of 11 shallow wells.
Its fluid collection and recycling system has a total of 142 online wells as of January this year which include 111 production wells and 31 injection wells; 33 horse-power separator vessels; two-phase line length spanning 16 kilometers; steamline length of 36 kilometers; and injection line length of 23 kilometers.
The main plant utilizes high-pressure steam with 11 ksca, while the separated brine is flashed at a lower pressure which is 5.96 ksca for utilization by the bottoming plant.